Tutorial – Orthographic Projections & Basic Isometrics

This is the first part in a series of tutorials about Isometrics.Isometric projections are a system of drawing that allows an artist to quickly and accurately draw an object without using perspective. I will go into more depth about isometrics later in this tutorial. I’m going to begin by talking about a system that is commonly used with isometrics.

Orthographics

Orthographic projections are a way of describing what an object looks like from several different views. Orthographics are also called engineering drawings or plan views. Using a set of orthographics an illustrator can easily draw the three-dimensional object from any angle and in perspective, isometric or any number of other drawing systems. 3D modelers often use orthographics to accurately create an object in a 3D application.

An orthographic is one way to describe a three dimensional object in two-dimensional space. Typically an orthographic will have the top, side and front views of an object drawn together with some kind of scale.

Top, front & side orthographics

An orthographic can have more then three sides drawn if the object has unique sides that would not be described clearly by just three images.

Top, front & 2-side orthographics

Once you have a clear set of orthographics you can draw your object in whatever method and from whatever view is required for your project. If you are planning to draw a set of orthographics from a physical object begin by measuring. Use a ruler and a set of calipers to measure all the surfaces of the object and make notes and a sketch. Once you are finished gathering data you can use your notes to create a set of orthographics in Illustrator. And that brings us to the world of isometrics.

Isometric projections are from the family of axonometric projection systems. Isometric comes from Greek for “equal measure”. This is because isometrics don’t use a vanishing point system, instead lines fall onto a 30° degree grid.

Perspective vs Isometric

Often the first impression of an isometric is that it looks “off”. This is more noticeable when an isometric cube is sitting next to a perspective cube. If you are going to be working in isometric there is a certain amount of distortion that comes with the territory. This is one of the factors that give isometrics their specific look. The huge upside to drawing in isometric especially using illustrator is that once you have created an object it will look exactly the same anywhere you place it. There are no vanishing points and no horizon lines. An object will be the same anywhere on your page. This is very important because you only ever have to drawn an object once. For example you could have an assembly drawing with one hundred screws in it. But you would only have to draw one screw and then copy it as many times as needed. This is a very powerful tool for speeding up workflow.

There are many other systems that don’t require vanishing points or horizon lines and give you similar benefits. But isometrics are the only one of these systems to make the jump from the technical illustrators toolbox to a useful skill for all graphic artists. The use of isometrics in early videogames has spawned a whole subculture of isometric pixel artists. And as the info-graphics style becomes very popular in magazines and newspapers you see isometrics being used more and more by artist with no technical illustration background.

Ok, now we can get into how to actually draw in isometric. The best way to start working in isometric is to make an isometric grid in Adobe Illustrator.

Step 1

Step 2

Using your line tool option click somewhere on your page. A dialogue box will pop up. Make a 30in line on a 30° angle.

Illustrator's Line Segment Tool Options

Step 3

Move your line over to the left side of your page. Now while holding option tap the right arrow key once. Because we set the increments to 1in the line was copied 1 in to the left. Repeat until you have crossed the page.

Creating an isometric grid

Step 4

You could repeat step 3 from right to left with a 1500 line. Or you can select all the lines and double click on the mirror tool and copy mirror horizontally.

Creating an isometric grid

Step 5

Now you have an isometric grid. Select>All (command A) and hit (command 5) or View>Guides>Make Guides to turn your grid lines into guides. Save this file as iso grid template to use any time you want to work in isometric.

Isometric grid converted to guides

Step 6

Now we can start building objects on the isometric grid – first off a cube. Start by making a small 4 cornered shape with your pen tool.

Drawing with the isometric grid

Step 7

Using your direct selection tool (white arrow) line up your 4 corners with a square on the grid.

Drawing with the isometric grid

Step 8

Using your pen tool and the same method as above create the left and right sides of the cube. Quickly block out a four-cornered shape then move the corners into place with the direct selection tool. When building shapes on an isometric grid it is a good idea to start thinking of your objects in planes top, left side, right side. This will make more complicated objects easier to visualize.

Drawing with the isometric grid

Drawing with the isometric grid

Step 9

Select all three parts and group (Command G). You now have an isometric cube. You can start making copies of the cube and quickly begin building larger shapes. You can scale the cube up or down and build with it.

Drawing with the isometric grid

Incorporating Orthographics

Now that you know the fundamentals of building a cube on an isometric grid we can incorporate the orthographics discussed earlier.

Step 1

Make a simple orthographic, with a scale that will work with your grid.

Simple orthographic plans

Step 2

Build the left side first. Using the pen tool rough out the shape by counting grid squares. Then line up the points with the direct selection tool.

Drawing in isometric from orthographic plans

Drawing in isometric from orthographic plans

Step 3

Build the front of the shape. Count out grid squares, rough out the shape with the pen tool and clean up with the direct selection tool.

Drawing in isometric from orthographic plans

Drawing in isometric from orthographic plans

Step 4

Complete the top. By this point I’m sure you’ve come across parts of the shape that don’t just sit on their respective plane. This is where being able to actually read the orthographics and interpret them is essential. Or else you’ll just end up with a set of orthographics distorted onto three different planes.

Isometric vs. distorted orthographics

Step 5

Using the same orthographics draw the object from several different angles and orientations. Get very comfortable building basic shapes on an orthographic grid it will come in very useful once you start working on more complex objects.

Good stuff! The one thing I always wished adobe illustrator had is a way of drawing in isometric like ISODRAW. That program was great for that 1 purpose. You could take a square or shape and project it onto a plane, put a hole through it and it would automatically thick and thin your lines. Usually when I draw in Iso I just turn on smart guides and adjust the angles.

Also (sorry to go on) you didn’t reveal to the reader how you are making thin and thick lines. Sometimes this can be a very elaborate process of breaking objects up or cutting lines off their base shape.

There are many ways to do iso illustrations and this is a good basic tutorial on one method. Honestly I’ve never considered adobe illustrator to be a very good program for creating isometric illustrations. I always created my iso’s in either autocad or isodraw and did the color and line work in illustrator. We could do an entire tutorial on thick and thin lines itself.